Proposals have been made to attach an IC chip integrally formed with an antenna coil to parts and products for their inventory management. The IC chip integrally formed with an antenna coil has also been proposed to be embedded in an identity card for room entry management and commuter pass applications.
However, IC chips integrally formed with an antenna coil are hard and easily score their coil formation surfaces when IC chips contact each other. This renders impossible the packing of IC chips in a bag or the use of a parts feeder, thus leaving no alternative but to depend on expensive material handling.
Another drawback is that the IC chip formed integral with an antenna coil is very thin (about 0.2–0.6 mm thick) and fragile, and thus easily develops cracks and chipping due to stresses in the coil formation surface (or its back). This makes secondary processing difficult.
Further, although an insert molding using resin is possible, since the IC chip integrally formed with an antenna coil greatly differs in physical property from a mold resin, a moldability of the IC chip is bad, making it difficult to produce a large number of molded products. This in turn increases cost.
Further, in the case of an insert molding, a thermal expansion of embedded resin and stresses and strains during use have direct adverse effects on the IC chip, resulting in the IC chip circuit being broken in the worse case.